我一直在遵循Google Storage Samples指南,并尝试使用Java来实现this MediaStore指南,因为提供的指南是用Kotiln编写的。我编译并运行了提供的代码,它运行良好,我的设备上有近5,000多个图像。谷歌提供的示例将它们显示在RecyclerView中,并使用滑行加载图像。
但是,当我在Java中实现类似功能时,RecyclerView的运行速度非常慢,您几乎不会滚动,然后在应用程序停止运行一段时间之后。我肯定缺少什么。
Google的代码示例[Kotlin]
private inner class GalleryAdapter(val onClick: (MediaStoreImage) -> Unit) :
ListAdapter<MediaStoreImage, ImageViewHolder>(MediaStoreImage.DiffCallback) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ImageViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val view = layoutInflater.inflate(R.layout.gallery_layout, parent, false)
return ImageViewHolder(view, onClick)
}
override fun onBindViewHolder(holder: ImageViewHolder, position: Int) {
val mediaStoreImage = getItem(position)
holder.rootView.tag = mediaStoreImage
Glide.with(holder.imageView)
.load(mediaStoreImage.contentUri)
.thumbnail(0.33f)
.centerCrop()
.into(holder.imageView)
}
}
}
/**
* Basic [RecyclerView.ViewHolder] for our gallery.
*/
private class ImageViewHolder(view: View, onClick: (MediaStoreImage) -> Unit) :
RecyclerView.ViewHolder(view) {
val rootView = view
val imageView: ImageView = view.findViewById(R.id.image)
init {
imageView.setOnClickListener {
val image = rootView.tag as? MediaStoreImage ?: return@setOnClickListener
onClick(image)
}
}
}
我的代码[Java]
适配器
public class GalleryAdapter extends RecyclerView.Adapter<GalleryAdapter.ImageViewHolder> {
class ImageViewHolder extends RecyclerView.ViewHolder
{
private ImageView imageView;
public ImageViewHolder(@NonNull View itemView) {
super(itemView);
imageView = itemView.findViewById(R.id.image_view);
}
}
private Context mContext;
private ArrayList<Picture> pictures;
public GalleryAdapter(Context context, ArrayList<Picture> pictures) {
this.mContext = context;
this.pictures = pictures;
}
@NonNull
@Override
public ImageViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(mContext).inflate(R.layout.single_image_view, parent, false);
return new ImageViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull final ImageViewHolder holder, int position) {
Picture p = pictures.get(position);
Glide.with(holder.imageView)
.load(p.getUri())
.thumbnail(0.33f)
.centerCrop()
.into(holder.imageView);
}
@Override
public int getItemCount() {
return pictures.size();
}
}